289 Runs Hot
Just a couple shots in the dark here... I know the timing covers for the 289 and various 302s are different... maybe something about the water passages are different? And with that said, is the water pump for a 289 different than a 302 (other than of course the radiator hose goes on the opposite side)? My 289 in my pickup got pretty hot during the initial cam breakin, but after that it's always been perfectly fine. Is the engine lower than the radiator like it's supposed to be? Have you done a compression check? Maybe something weird like a piston that is too tight in the bore, I dunno. I feel for ya man, I hate those problems that just refuse to go away regardless of the logic and money you throw at it, lol.
'97 F250HD 4x4 460; '85 Ranger, 350hp 289, T5, firstname.lastname@example.org
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